1. Field of the Invention
The present invention relates to a tap-off transformer, and more particularly, to a tap-off transformer using isolating walls and a winding design to increase the rated voltage of transformer.
2. Description of the Prior Art
FIG. 1A is a cross sectional side view and FIG. 1B is a side view of the windings of a conventional transformer. Referring to the figures, the transformer 1 comprises a coil base 11, a core 12 and wires 13. The coil base 11 has isolating walls 111 placed outside of it and using isolating walls 111 to form a primary side area 14 and a secondary side area 15. The secondary side area 15 is partitioned into a plurality of winding slots 16 by isolating walls 111 with wires 13 being winded sequentially in winding slots 16. The coil base 11 has hollow structure for placing core 12 to form transformer 1. The above mentioned transformer structure uses isolating walls to set up a winding slot in primary side area and a plurality of winding slots in secondary side area with wires winded sequentially and unidirectionally inside winding slots to achieve the required rated voltage of the transformer. Hence, the secondary side area (˜0V-Vout) uses multiple winding slots to provide voltage isolation, however, since voltage of every isolated slot could be varied and it tends to result in over voltage between slots, thus the characteristics of component will become unstable to cause abnormal function of the product.
Therefore, the prior art transformer mentioned above presents several shortcomings to be overcome.
In view of the above-described deficiency of prior-art transformers, after years of constant effort in research, the inventor of this invention has consequently developed and proposed a tap-off transformer.